On the porous medium approach for outflow boundary conditions in 2D numerical blood flow simulations

In this article the authors present a novel approach for defining outflow boundary conditions in numerical simulations within vascular networks, utilizing a porous medium approach, already tested and validated for 1D blood flow simulations. By recognizing the similarity of the resistance offered by the downstream microvascular network of a vessel and with the one offered by a porous medium perfused by blood, the authors introduce a porous medium approach as an alternative to the discrete vascular model, when it is not possible to directly simulate the actual downstream network. Through a comprehensive comparison, incorporating fluid-dynamic equations and heat transfer analysis, this study demonstrates the robustness of the porous media approach. Results reveal similar trends in pressure, velocity, and temperature variables between the two models, highlighting the efficacy of the porous medium method to set outflow conditions in blood flow simulations